1. Technical Field
Embodiments of the present invention relate generally to an apparatus and method for transmitting data using a human body and, more particularly, to an apparatus and method that are capable of transmitting data at a maximum of 2.2969 Mbps while meeting a transmit mask corresponding to requirements for the transmission signal frequency characteristics of the physical layer of human body communication in a network using a human body as a medium.
2. Description of the Related Art
Human body communication technology is technology that transfers signals between devices connected to a human body using the conductive human body as a communication channel.
As described above, human body communication enables communication between various portable devices, such as a personal digital assistant (PDA), a portable personal computer, a digital camera, a smart phone, etc., and communication with a fixed device, such as a printer, a TV, an entry and exit control system, or the like, through the establishment of a network by a user's simple touch, as in Korean Patent Application Publication No 2012-0045964 entitled “Real-Time Data Transmission System and Method using Human Body Communication.”
The physical layer structure and requirements of human body communication are set out in the IEEE standard 802.15.6 (wireless body area networks (WBAN)) standard. A human body communication transmitter that transmits data at a maximum of 1.3125 Mbps using frequency selective digital transmission (FSDT) in the WBAN standard can increase maximum transmission rate using a method of increasing the number of symbols of 16 orthogonal code vectors presented by the WBAN standard as transmission symbols, or the like.
However, this method is problematic in that a transmit mask corresponding to requirements for the frequency characteristics of a transmission signal presented by the WBAN standard is not met because the frequency characteristics, i.e., the working frequency band, of a transmission signal is increased.
Alternatively, although a method of increasing the length of a frequency shift code may be considered in order to improve detection performance, i.e., bit error rate (BER), with respect to a reception signal, this method is also problematic in that transmission rate is reduced when the length of the frequency shift code is increased.